Approach to Biliary Pain

Approach to Biliary Pain – A Medical Student Clinical Pearl

Katie Oxford, Med III

Reviewed by: Dr. Colin Rouse

Copyedited by: Dr. Mandy Peach


Mr. X is a 20-year-old male, who has presented to the ER on multiple occasions with RUQ pain. This pain was constant, severe (8/10), and was exacerbated by eating. This pain started a few months ago, is not radiating, and is variable in duration. The patient had become increasingly frustrated due to multiple trips to the ER.

The patient has had no vomiting or nausea, no change in bowel movements. On review of systems, no abnormalities are noted. Vitals are stable.


On ultrasound and CT done during prior visits no gallstones were present within the gallbladder or within the biliary tree, but the common bile duct was dilated. The gallbladder appears normal on all imaging studies performed thus far, however the patient continues to have pain.

On physical exam, there were no concerns on inspection (no scars, visible masses, signs of liver disease, ascites). Normal bowel sounds were heard, and the abdomen was soft and non-tender on palpation. Murphy’s sign was negative. LFT’s, amylase and lipase studies were normal.

Sphincter of Oddi Dysfunction

Sphincter of Oddi dysfunction (SOD) is within the differential diagnosis for patients who present with recurrent biliary pain, with no apparent source 1. This disease process can present with biliary as well as pancreatic obstructive symptoms 2. There are multiple propositions as to the pathogenesis of this disease; it may be due to stenosis at the ampulla, or it could be caused by sphincter of oddi hypertension (either due to hypertrophy, or increased smooth muscle response to stimuli) 2.

Rome IV criteria for functional biliary sphincter of Oddi disorder5:

●Criteria for biliary pain are fulfilled

●Absence of bile duct stones or other structural abnormalities

●Elevated liver enzymes or dilated bile duct, but not both


Supportive criteria include

●Normal amylase/lipase

●Abnormal sphincter of Oddi manometry

●Abnormal hepatobiliary scintigraphy


It is important to avoid invasive testing in patients with suspected SOD, as their risk for post-ERCP pancreatitis is high 2.

There are several methods that can be used to assess patients for SOD:

Endoscopic ultrasound
Transabdominal ultrasound
Hepatobiliary Scintigraphy (HIDA) can be used to evaluate patients for SOD. 2

Additionally, cholecystokinin or secretin can be used in conjunction with the above tests in order to provoke the dysfunction 2

Back to our case:
In a case of RUQ pain, there are a few disease processes to keep in mind 3:

Differential Diagnoses:
• Cholecystitis
• Cholelithiasis
• Cholangitis
• Colitis
• Diverticulitis
• Abscess
• Hepatitis
• Mass
• Pneumonia
• Functional Gallbladder Disorder
• Abscess
• Embolus
• Nephrolithiasis
• Pyelonephritis

Because Mr. X had pain that resembled biliary colic very closely, yet multiple previous imaging studies and lab studies showed no signs of acute cholecystitis,  cholelithiasis, pancreatitis, or liver disease, it was thought that perhaps sphincter dysfunction could be the root cause of the problem.

HIDA Scans:

Hepatobiliary Scintigraphy (HIDA) is a nuclear medicine procedure involved IV injection of a radiotracer which is excreted into the biliary system. This allows for the visualization of the bilirubin metabolic pathway and can be used to diagnose various biliary pathologies 4

After discussion with the patient and reassurance, a HIDA scan was ordered in order that confirmed suspicions of SOD.

Management 6:

The goal is to relieve pain. There are 3 main approaches:

  1. pharmacological: calcium channel blocker and nitrates to reduce basal sphincter of oddi pressure and relaxation of the sphincter.
  2. endoscopic sphincterotomy: particularly beneficial in those with elevated sphincter of oddi pressure
  3. surgical sphincterotomy

The patient was referred to gastroenterology and initiated on a calcium channel blocker in the interim.



  1. Bistritz L, Bain VG. Sphincter of Oddi dysfunction: Managing the patient with chronic biliary pain [Internet]. Vol. 12, World Journal of Gastroenterology. WJG Press; 2006. p. 3793–802.
  2. Small AJ, Kozarek RA. Sphincter of Oddi Dysfunction. Vol. 25, Gastrointestinal Endoscopy Clinics of North America. W.B. Saunders; 2015. p. 749–63.
  3. Cartwright SL, Knudson MP. Evaluation of Acute Abdominal Pain in Adults [Internet]. Vol. 77, American Family Physician. 2008 Apr.
  4. Snyder E, Kashyap S, Lopez PP. Hepatobiliary Iminodiacetic Acid Scan [Internet]. StatPearls. StatPearls Publishing; 2021.
  5. Cotton, P. B., Elta, G. H., Carter, C. R., Pasricha, P. J., & Corazziari, E. S. (2016). Rome IV. Gallbladder and Sphincter of Oddi Disorders. Gastroenterology, S0016-5085(16)00224-9. Advance online publication.
  6. Catalano, M. F, Thosani, N. (2021). Treatment of Sphincter of Oddi Dysfunction. Retrieved from UptoDate


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Alternative Rib Fracture Management in the ED

Alternative Rib Fracture Management in the ED – A Medical Student Clinical Pearl

Victoria Mercer, Clinical Clerk 3, DMNB

Reviewed and Copyedited by Dr. Mandy Peach

Rib fractures are a frequent presentation in the ED, occuring in approximately 10% of all injured patients with the primary causes being blunt chest trauma and MVAs(1,2).  The mainstay of treatment for rib fractures is analgesic control(1). When pain cannot be adequately managed, the patient is at a heightened risk of hypoventilation due to decreased thoracic mobility and secretion clearance, predisposing the patient to significant atelectasis(1,2).

Historically the pain from rib fractures has been managed with acetaminophen or NSAIDS and if these do not sufficiently alleviate the pain, opioids are used(1,3). Unfortunately, these methods often do not provide adequate pain control or in the case of opioids, come with a myriad of side effects such as nausea, vomiting, constipation, respiratory depression and the potential for dependency and abuse (1,4).

An alternative to traditional methods include regional techniques such as paravertebral or epidural nerve blocks. These interventions have been shown to effectively control pain in rib fractures(3,4). The downside to these interventions include being technically challenging and time consuming with significant complication risks and contraindications such as coagulation disorders (1,3).

The solution? A serratus anterior block 

An ultrasound guided blockade of the lateral cutaneous branches of the thoracic intercostal nerves was first described by Blanco et al. in 2013 for patients following breast surgery to manage their postoperative pain(5). This procedure has been adopted by many emergency departments for its convenience and practicality compared to epidural or paravertebral nerve blocks(3).

Serratus anterior blocks are less invasive and considerably more practical in the ED setting, providing paresthesia to the ipsilateral hemithorax for 12-36 hours (6).

The only absolute contraindications are patient refusal, allergy to local anesthetic and local infection(1).

Complications of a serratus anterior block include pneumothorax, vascular puncture, nerve damage, failure/inadequate block, local anesthetic toxicity and infection(1).

Serratus anterior blocks are only effective for the anterior two-thirds of the chest wall (3).


Figure 1. Ultrasound image of serratus anterior muscle and surrounding tissues with superficial or deep needle guides. Image from Thiruvenkatarajan V, Cruz Eng H, Adhikary SD. An update on regional analgesia for rib fractures. Current Opinion in Anaesthesiology. 2018;31(5):601–607.

How do you do it?

The procedure is usually performed with the patient laying supine however the patient could also lay in a lateral decubitus position (1,3). Using a high frequency linear ultrasound probe (6-13MHz), identify the serratus anterior and latissimus dorsi muscles over the fifth rib in the mid-axillary line(1,3). Using an in-plane approach, insert the needle either superficial or deep to the serratus anterior and confirm correct needle placement by visualizing anaesthetic spread via ultrasound(1,3). According to May et al., superficial spreading tends to have a longer lasting analgesic effect(1). Place and secure a catheter to infuse the remainder of the bolus(1,3). Thiruvenkatarajan et al. recommend a bolus of 40ml of 0.25% levobupivacaine and a 50mm 18G Tuohy catheter needle(3).

See this excellent review by Dr. David Lewis on identifying rib fractures and their complications using ultrasound (start 3:08) as well as a review of the block and procedure (start 8:00)

Rib Fractures and Serratus Anterior Plane Block


  1.         May L, Hillermann C, Patil S. Rib fracture management. BJA Education. 2016 Jan 1;16(1):26–32.
  2.         Malekpour M, Hashmi A, Dove J, Torres D, Wild J. Analgesic choice in management of rib fractures: Paravertebral block or epidural analgesia? Anesthesia and Analgesia. 2017 Jun 1;124(6):1906–11.
  3.         Thiruvenkatarajan V, Cruz Eng H, Adhikary S das. An update on regional analgesia for rib fractures. Vol. 31, Current opinion in anaesthesiology. 2018. p. 601–7.
  4.         Tekşen Ş, Öksüz G, Öksüz H, Sayan M, Arslan M, Urfalıoğlu A, et al. Analgesic efficacy of the serratus anterior plane block in rib fractures pain: A randomized controlled trial. American Journal of Emergency Medicine. 2021 Mar 1;41:16–20.
  5.         Blanco R, Parras T, McDonnell JG, Prats-Galino A. Serratus plane block: A novel ultrasound-guided thoracic wall nerve block. Anaesthesia. 2013 Nov;68(11):1107–13.
  6.         Mayes J, Davison E, Panahi P, Patten D, Eljelani F, Womack J, et al. An anatomical evaluation of the serratus anterior plane block. Anaesthesia [Internet]. 2016 Sep 1 [cited 2021 Apr 18];71(9):1064–9. Available from:



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